Mechanical Engineer - Powertrain Engineering

Lemonergy; Torrance (CA); On-site; USD 105,000 - 125,000; Full time

Benefits offered by this job

Healthcare benefits

Parental leave

Generous PTO

401(k)

Water fund

Professional development

Safety PPE reimbursement

Captain training

Office lunches

Relocation assistance

Job summary

Arc seeks a Mechanical Engineer to own high‑voltage power distribution components for large marine vessels, including e-tugs. You will design electromechanical packaging, work across mechanical, electrical, thermal, and manufacturing domains, and support from concept to production.

You will join a hard‑charging, hands-on team at our Los Angeles headquarters, reporting to the Powertrain Hardware Engineering Manager, with opportunities to grow into broader system ownership.

Qualifications

• Bachelor’s degree in Mechanical Engineering or related field.
• 2+ years’ experience designing mechanical/electromechanical components or subsystems.
• Foundational knowledge of electrical systems; interest in high‑voltage battery systems and power electronics.
• Strong fundamentals in structural and thermal engineering.
• Experience with CAD software (NX, CATIA, or SolidWorks).
• Experience with analysis tools (MATLAB, Simulink, or FEA).
• Working knowledge of manufacturing methods and DFM principles.
• Hands-on hardware design, build, debug, and field care experience.
• Able to learn quickly and make solid engineering decisions.

Responsibilities

• Design electromechanical packaging for high‑voltage assemblies and distribution systems for marine environments.
• Own component and subsystem designs from concept through production.
• Collaborate across mechanical, electrical, thermal, and manufacturing domains to deliver high‑voltage power systems.
• Perform busbar design, thermal calculations, and harness routing with senior guidance.
• Contribute to requirements, CAD design, prototyping, validation, and production support.
• Build, test, troubleshoot, and iterate hardware in fast-moving development environments.
• Coordinate with suppliers, shipyards, and operators to support execution.
• Assist with sea trials and field validation to verify system performance.

Skills

Mechanical design

Electromechanical

Power electronics

High voltage

CAD SolidWorks

Thermal analysis

DFM

Education

Bachelor's degree in Mechanical Engineering

Tools

NX

CATIA

SolidWorks

MATLAB/Simulink

Job description

What we're building

The marine industry supports recreation, global commerce, and national defense. And yet it runs on technology that hasn't meaningfully changed in fifty years. Until now.

Arc is on a mission to electrify the marine industry. We're rethinking powertrains, software, and vessel designs from first principles. And we're already executing. We started with consumers to develop and harden our core technology. We're scaling production of our flagship model with new models and sectors on the horizon. Now we're extending our platform to commercial applications, starting with tugs, ferries, and defense, with years' worth of signed contracts and a pipeline that spans every vessel type on the water.

The technology is proven, the momentum is building, and the opportunity is enormous. The marine industry is going electric, and Arc is building the platform that powers it.

Who we're looking for

As a Mechanical Engineer at Arc, you will design and own components and subsystems within complex electromechanical systems, contributing across the full vessel lifecycle, from early concept and requirements through prototyping, validation, sea trials, and production. Your focus will be high-voltage power distribution for our largest vessels, such as our e-tug.

This is a full-time, on-site role at our Los Angeles headquarters, reporting to our Manager, Powertrain Hardware Engineering.

What you'll do

• Designing electromechanical packaging for high-voltage assemblies, such as DC-to-AC power conversion cabinets and AC distribution systems, built for manufacturability, serviceability, and the marine environment
• Owning the design of components and subsystems within complex electromechanical systems, and contributing to their integration from concept through production
• Working across mechanical, electrical, thermal, and manufacturing domains to help deliver high-voltage, high-power distribution systems
• Performing busbar design, thermal calculations, static and shock/vibration analysis for component mounting, and harness and fluid system routing, with guidance from senior engineers
• Contributing to requirements definition, specifications, CAD design, hands-on prototyping, analysis (FEA, numerical modeling, hand calculations), validation, and production support
• Building, testing, troubleshooting, and iterating on hardware in fast-moving development environments
• Collaborating with component suppliers, partner shipyards, manufacturing teams, and vessel operators to support execution
• Supporting sea trials and in-field validation to verify system performance and resolve real-world issues
• Growing into broader system ownership as you develop your technical depth and judgment
• Traveling occasionally (~15%) to support testing, validation, suppliers, and field operations

Minimum Qualifications

• Bachelor’s degree in Mechanical Engineering or a related engineering field
• 2+ years of industry experience designing mechanical or electromechanical components or subsystems (internships, co-ops, and hands-on student engineering projects such as Formula SAE count)
• Foundational knowledge of electrical systems, with interest in high-voltage battery systems and power electronics
• Strong fundamentals in structural and thermal engineering
• Experience with CAD software such as NX, CATIA, or SolidWorks
• Experience with analysis and modeling tools such as MATLAB, Simulink, or FEA packages
• Working knowledge of manufacturing methods and design-for-manufacturability (DFM) principles
• Hands-on experience designing, building, debugging, and troubleshooting hardware, whether in industry, prototype, or student project environments
• Ability to learn quickly and make sound engineering decisions in ambiguous environments
• Clear written and verbal communication skills
• Strong time management and prioritization skills
• Comfortable working hands-on in the field, including on boats and at shipyards

Bonus Qualifications

• Experience with marine systems or commercial vessels; familiarity with Coast Guard and ABS regulations is a plus
• Experience with fluid system design, including pump sizing, heat exchanger sizing, and hose/pipe routing
• Hands-on experience with high-voltage battery systems, power electronics, busbars, or harness design
• Experience taking a design through prototype or production release
• Exposure to sheet metal manufacturing, CNC machining, composites, or shop tools
• Experience creating detailed engineering drawings with working knowledge of GD&T
• Hands-on engineering project experience such as Formula SAE, Baja SAE, or Solar Car
• Experience with NX
• Comfortable pushing at a fast but sustainable pace
• Enthusiasm for boating, marine systems, and the water

At Arc, we encourage diversity and consider all qualified applicants equally for employment, regardless of background, identity, or status. You’re always welcome to reach out even if you don’t meet all of these qualifications. Passion and aptitude make up for a lot.

What We Offer

The base salary for this role is P1: $105,000 or P2: $125,000 annually.

Highly competitive equity grants are included with full-time offers. As well as semi-annual bonuses tied to your impact, not just your tenure.

Additionally, Arc Offers Top-tier Benefits For Full-time Employees, Including

• Healthcare benefits - 99% employer-paid medical, dental, and vision
• Parental leave - 14 weeks fully paid for birthing and non-birthing parents
• Generous time off - Highly competitive PTO with an opportunity to earn more time with tenure
• Income protection - Life and disability insurance for all employees
• Retirement savings - Traditional and Roth 401(k) access
• Water fund - $500 for you to spend each year to get out on the water, however you choose
• Professional development - $500 annual reimbursement for professional development and a monthly AI stipend
• Safety Support - Annual reimbursement for PPE, ergonomic equipment and anything that ensures we keep our crew safe
• Captain training - Training and access to take Arc boats out with friends and family
• Office perks - Daily lunches, snacks, and good coffee while on-site
• Relocation assistance - Available depending on role eligibility.

Our values

We move with urgency and build with care. We value these five things above all else:

• Ownership over both your work and the company’s success
• Empathy for colleagues and for customers
• Humility in problem solving and collaboration
• Pragmatism for navigating ambiguity quickly and sensibly
• Inclusion of different backgrounds, opinions, cultures, and perspectives

We want people who share and embody these values. It is vital that our values align — we’d be happy to elaborate on any or all of these during the interview process.